Field of the Invention
The present disclosure generally relates to a photoelectric conversion apparatus and an imaging apparatus using the photoelectric conversion apparatus.
Description of the Related Art
As an imaging element, a light-receiving element which includes elements which have photoelectric conversion portions in semiconductors and which are arranged in a matrix as pixels, which performs charge transfer on signals generated by photoelectric conversion of the pixels using a charge-coupled device (CCD) circuit or a complementary metal-oxide semiconductor (CMOS) circuit, and which reads the signals has been widely used.
Japanese Patent Laid-Open No. 2012-209421 discloses a configuration in which a photoelectric conversion portion having a photoelectric conversion film sandwiched between two transparent electrodes is disposed on a semiconductor substrate. With this configuration, the photoelectric conversion film is inclined relative to the semiconductor substrate so that sensitivity is improved.
FIG. 5 is a cross-sectional view of the configuration of the photoelectric conversion apparatus disclosed in Japanese Patent Laid-Open No. 2012-209421. A lower electrode 121, a photoelectric conversion layer 11, and an upper electrode 12 are formed on an inner wall of each of recessed portions 7 on a semiconductor substrate 5, and a protection layer 17 is formed all over the upper electrode 12. Furthermore, the lower electrode 121 and the upper electrode 12 are connected to each other on the semiconductor substrate 5 through a plug 14. In the configuration disclosed in Japanese Patent Laid-Open No. 2012-209421, disconnection of the upper electrode 12 is likely to occur in top regions (regions B) where side surfaces and upper surfaces of the recessed portions 7 intersect with each other. The disconnection occurs since a thickness of the upper electrode 12 is likely to be thin due to step differences of the top regions (the regions B) of the recessed portions 7.